Question : what is Rules and Conventions for writing SI Units and their Symbols

 Question : what is Rules and Conventions for writing SI Units and their Symbols

Answer: 

1. The units named after scientists are not written with a capital initial letter. E.g.

newton, henry, ampere and watt.

2. The symbols of the units named after scientists should be written by the initial

capital letter. E.g. N for newton, H for henry, A for ampere and W for watt.

3. Small letters are used as symbols for units not derived from a proper noun. E.g. m

for metre, kg for kilogram.

4. No full stop or other punctuation marks should be used within or at the end of symbols. E.g. 50 m and not as 50 m.

5. The symbols of the units are not expressed in plural form. E.g. 10 kg not as 10 kgs.

6. When temperature is expressed in kelvin, the degree sign is omitted. E.g. 283 K not as 283° K (If expressed in celsius scale, degree sign should be included e.g. 100°C not as 100 C, 108° F not as 108 F).

7. Use of solidus (/) is recommended for indicating a division of one unit symbol by another unit symbol. Not more than one solidus is used. E.g. ms power of -1 or m/s. J/K/mol should be JK power of -1mol power of -1.

8. The number and units should be separated by a space. E.g. 15 kgms power of –1 not as 15 kgms power of –1.

9. Accepted symbols alone should be used. E.g. ampere should not be written as amp and second should not be written as sec.

10. The numerical values of physical quantities should be written in scientific form. E.g. the density

of mercury should be written as 1.36 × 104 kgm power of -3 not as 13600 kgm power of -3.